1. Field of the Invention
The present invention relates to a sliding door opening/closing device for a vehicle that serves to open and close a sliding door of a vehicle.
2. Description of the Related Art
The related art of sliding door opening/closing devices for vehicles is disclosed, for example, in Japanese Patent Application Laid-open No. 2000-142392 (JP-A-2000-142392), the invention being titled “Sliding Door Opening/Closing Device for Vehicle”. The sliding door opening/closing device for a vehicle disclosed in JP-A-2000-142392 is provided with a door lock device that locks and unlocks the sliding door in response to opening and closing of the sliding door. This door lock device locks the door so that it cannot be opened or closed, by dropping a latch into a lock hole. This door lock device is configured to lift the latch with a wire device and makes it possible to unlock the door by manually operating a handle device.
In the conventional sliding door opening/closing device for a vehicle, the latch has to be lowered after the latch has been correctly positioned above the lock hole, but this positioning is not easy to perform, as described hereinbelow.
A door edge rubber is provided at the left and right sliding doors as a measure against door clamping, and when the door is closed, the door edge rubber is compressed and deformed, thereby eliminating a gap between the sliding doors. However, a problem arising in a case where the crushing amount of the door edge rubber is large when the door is closed is that a resistance force applied to the sliding door increases, the latch shifts from a position above the lock hole, and locking with the latch is impossible.
Vibration preventing parts that have soundproofing, wind-stopping, and vibration damping functions are provided to abut against the sliding door when the vehicle is travelling (that is, when the door is closed), and a problem arising when these vibration preventing parts apply a force that exceeds a supposed value when the door is closed is that a resistance force applied to the sliding door increases, the latch shifts from a position above the lock hole, and locking with the latch is impossible.
Conversely, where the crushing amount of the door edge rubber is small, a resistance force applied to the sliding door is small. Furthermore, when the vibration preventing parts apply a force that is less than a supposed value when the door is closed, a resistance force applied to the sliding door is also small. The problem arising in these cases is that the resistance force falls within the specified range and the latch is closed even when a specified obstacle is squeezed by the sliding doors, and the sliding door does not comply with a door clamping test.
Because problems arise both in the case where the resistance force applied to the door is small and in the case where the force is large, as described above, this force has to be adjusted to fall in a predetermined range. The problem is, however, that the resistance force is not easy to adjust from both sides of the range, while correctly positioning the latch above the lock hole.
A structure can be used in which a gap is provided between the door edge rubbers at the left and right sides to facilitate the adjustment operation in order to satisfy the requirements placed on both the locking operation and the specified accuracy of door clamping detection, but with the door edge rubber of a shape protruding to the left and right, water and wind penetrate from the gap and noise is generated, thereby making it difficult to follow this approach.
Because the conventional door lock device uses a system such that the latch is lowered by spring pressure and the door lock device is locked by using an insertion force created by the inertia force of the doors that are shut at a certain door closing speed, the sound of the dropping part and the sound of collision are loud.
Because a force exceeding a large door counterforce that is applied to the latch in addition to the spring pressure pulling the latch has to be applied when the conventional door lock device is locked, a metal noise sound is loud.
A counterforce from the door edge rubber that is compressed when the door is closed is applied to the sliding door, a large door counterforce is applied to the latch in the lock device during locking, and the latch is difficult to move. The resultant problem is that where the handle is operated in a case of emergency in a state with such a large door counterforce, the outer wire is sometimes contracted, the inner wire is not drawn relative thereto, and emergency unlocking cannot be performed.